Chopping Blade of a Forage Harvester and Method for Producing Said Chopping Blade

ABSTRACT

Chopping blade ( 10 ), having a basic body ( 11 ), which has a fastening portion ( 12 ) for fastening said chopping blade to a chopping drum and a cutting portion ( 13 ) which is angled in relation to the fastening portion, and having a crop-guiding element ( 15 ) which is fastened to the fastening portion ( 12 ) and is intended for guiding chopped harvested crop, wherein a guide surface ( 16 ) of the crop-guiding element ( 15 ) has a curved contour. A distance (a) between the beginning of the guide surface ( 16 ) of the crop-guiding element ( 15 ) and a transition edge ( 14 ) between the fastening portion ( 12 ) and the cutting portion ( 13 ) of the basic body ( 11 ) is between 4 mm and 8 mm. The guide surface ( 16 ) runs rectilinearly in a first portion ( 18 ) with a length (b) between 4 mm and 8 mm, wherein said first portion ( 18 ) encloses an angle (α) between 18° and 22° with the fastening portion ( 12 ). The first portion ( 18 ) merges into a concavely curved second portion ( 19 ), the radius of curvature (Rx) of which is between 21 mm and 25 mm and which has a wrap angle (β) between 29° and 33°. The second portion merges into a concavely curved third portion ( 20 ), the radius of curvature (Ry) of which is between 18 mm and 22 mm and which has a wrap angle (γ) between 24° and 28°. The third portion merges into a convexly curved fourth portion ( 21 ). A maximum height of the crop-guiding element is between 24 mm and 30 mm.

The invention relates to a chopping blade of a forage harvester.Furthermore, the invention relates to a method for producing a choppingblade of a forage harvester.

EP 3 329 765 A1 discloses a chopping blade of a forage harvester, havinga basic body and having at least one crop-guiding element fastened tothe basic body. The basic body has a fastening portion for fastening thechopping blade to a chopping drum and a cutting portion which is angledin relation to the fastening portion and is intended for the harvestedcrop to be chopped. The respective crop-guiding element is fastened tothe fastening portion of the basic body and serves for guiding choppedharvested crop. A guide surface of the crop-guiding element has a curvedcontour. The curved contour of the crop-guiding element begins at adistance from a transition edge between the fastening portion and thecutting portion of the basic body. The chopping blade which is knownfrom EP 3 329 765 A1 is designed in respect of fastening of same to thechopping drum. This gives rise to problems in the guiding of the choppedharvested crop. There is a need for a chopping blade which optimallyconducts or guides the chopped harvested crop.

Taking this as the starting point, the present invention is based on theobject of providing a novel chopping blade of a forage harvester and amethod for producing the chopping blade.

This object is achieved by a chopping blade of a forage harvesteraccording to claim 1.

According to the invention, the distance between the beginning of theguide surface of the respective crop-guiding element and the transitionedge between the fastening portion and the cutting portion of the basicbody is between 4 mm and 8 mm.

The guide surface of the respective crop-guiding element runs, accordingto the invention, rectilinearly with a length between 4 mm and 8 mm in afirst portion of the crop-guiding element, which portion adjoins thebeginning of the guide surface, wherein the first portion of therespective crop-guiding element encloses an angle between 18° and 22°with the fastening portion of the basic body.

The first portion of the respective crop-guiding element merges,according to the invention, into a concavely curved second portion, theradius of curvature of which is between 21 mm and 25 mm and which has awrap angle between 29° and 33°.

The second portion of the respective crop-guiding element merges,according to the invention, in a concavely curved third portion, theradius of curvature of which is between 18 mm and 22 mm and which has awrap angle between 24° and 28°.

The third portion of the respective crop-guiding element merges,according to the invention, into a convexly curved fourth portion.

A maximum height of the respective crop-guiding element with respect tothe fastening portion of the basic body is, according to the invention,between 24 mm and 30 mm. The fourth portion of the crop-guiding elementpreferably merges into a fifth portion which defines the maximum heightof the crop-guiding element.

The distance between the beginning of the guide surface of therespective crop-guiding element and the transition edge of the basicbody, the length of the first portion of the guide surface of therespective crop-guiding element, the radii of curvature and wrap anglesof the concavely curved second and third portions of the guide surfaceof the respective crop-guiding element, the convexly curved fourthportion and the height of the respective crop-guiding element, asmeasured from the fastening portion of the basic body, in combinationwith one another permit optimum guidance of the chopped harvested crop.The optimum guidance and deflection of the chopped harvested crop makesit possible to save on energy in the conveying process since thedeflection of the chopped harvested crop is associated with littleacceleration work.

Furthermore, by means of the above combination of features, theharvested crop is deflected in a defined region of one revolution of thechopping drum, thus reducing the circulation of the harvested crop inthe region of the chopping drum.

Accordingly, the above combination of features is optimized in terms offlow and reduces the energy requirement necessary for the flow ofharvested crop. The harvested crop is conveyed with a high degree ofefficiency for a wide variety of harvested crops, cut length andthroughput rates.

The fourth portion of the respective crop-guiding element preferably hasa radius of curvature between 5 mm and 7 mm, wherein the fifth portionof the respective crop-guiding element runs parallel to the fasteningportion. This serves for further optimizing the guidance of theharvested crop.

The fifth portion of the respective crop-guiding element preferablymerges into a rectilinearly running sixth portion which encloses anangle between 23° and 27° with the fastening portion. The guidance ofthe harvested crop can thereby also be further optimized.

The respective crop-guiding element is preferably closed by portionsadjoining the sixth portion. This advantageously prevents harvested cropfrom accumulating on the trailing blade edge. Accumulations may lead toan imbalance. This feature therefore also serves for further optimizingthe guidance of the harvested crop.

The respective crop-guiding element is preferably a roll profilingelement. During roll profiling, surfaces are hardened, thus making itpossible to provide increased hardness for the respective crop-guidingelement. The susceptibility of same to wear can thereby be reduced.

The first portion, the second portion and the third portion of therespective crop-guiding element preferably bear a wear-protectioncoating. The susceptibility of the respective crop-guiding element towear can thereby also be reduced.

The method for producing the chopping blade is defined in claim 12.

Preferred developments of the invention emerge from the dependent claimsand the description below. Exemplary embodiments of the invention,without being restricted thereto, will be explained in more detail withreference to the drawing, in which:

FIG. 1 shows a cross section through a chopping blade according to theinvention;

FIG. 2 shows the cross section of FIG. 1 together with geometricalsizes;

FIG. 3 shows a detail from FIG. 2 ;

FIG. 4 shows the detail of FIG. 3 together with crop flow arrows;

FIG. 5 shows the detail of FIG. 3 together with further crop flowarrows;

FIG. 6 shows the detail of FIG. 3 together with further crop flowarrows;

FIG. 7 shows the detail of FIG. 3 together with further crop flowarrows;

FIG. 8 shows a further detail from FIG. 2 ; and

FIG. 9 shows a further detail from FIG. 2 .

FIG. 1 shows a cross section through a chopping blade 10 according tothe invention. The chopping blade 10 according to the invention has abasic body 11 and at least on crop-guiding element 15.

The basic body 11 of the chopping blade 10 has a fastening portion 12for fastening the chopping blade 10 to a chopping drum, not shown, and acutting portion 13 which is angled in relation to the fastening portion12 and is intended for cutting the harvested crop to be chopped.

The cutting portion 13 of the basic body 11 of the chopping blade 10 isangled in relation to the fastening portion 12 of the basic body 11.

A transition edge 14 in the form of a bending edge is formed between thefastening portion 12 and the cutting portion 13 of the basic body 11 ofthe chopping blade 10.

As already explained, the chopping blade 10 is fastenable to a choppingdrum, not shown, via the fastening portion 12. For this purpose, thefastening portion 12 is provided with fastening elements which are notshown, are preferably in the form of elongated holes and via which thechopping blade 10, specifically the basic body 11 thereof, can befastened to the chopping drum.

At least one crop-guiding element 15 is fastened to the fasteningportion 12 of the basic body 11. The crop-guiding element 15 has a guidesurface 16 for chopped harvested crop, the guide surface 16 having acurved contour at least in sections. The guide surface 16 is curvedconcavely inward here in section.

The guide surface 16 of the crop-guiding element 15 has a front edge 17at which the guide surface 16 begins. This edge 17 of the guide surface16 of the crop-guiding element 15 is at a distance a from the transitionedge 14 between the fastening portion 12 and the cutting portion 13 ofthe basic body 11.

According to the invention, the distance a between the beginning of theguide surface 16 of the crop-guiding element 15, i.e. the edge 17, andthe transition edge 14 between the fastening portion 12 and the cuttingportion 13 of the basic body 11 is between 4 mm and 8 mm, i.e. 6 mm±2mm.

The guide surface 16 of the crop-guiding element 15 runs rectilinearly,according to the invention, in a first portion 18 adjoining the edge 17,specifically along a length b which is between 4 mm and 8 mm, i.e. 6mm±2 mm. Said first portion 18 of the crop-guiding element 15 enclosesan angle α between 18° and 22°, i.e. 20°±2°, with the fastening portion12 of the basic body 11.

Said first portion 18 of the guide surface 16 of the crop-guidingelement 15 merges, according to the invention, into a concavely curvedsecond portion 19, specifically continuously and thus tangentially, thesecond portion 19 having a radius of curvature Rx between 21 mm and 25mm, i.e. 23 mm±2 mm, and a wrap angle β between 29° and 33°, i.e.31°±2°.

Said second portion 19 of the guide surface 16 of the crop-guidingelement 15 merges, according to the invention, into a concavely curvedthird portion 20, specifically again continuously or tangentially, theconcavely curved third portion 20 having a radius of curvature Rybetween 18 mm and 22 mm, i.e. 20 mm±2, and a wrap angle γ between 24°and 28°, i.e. 26°±2°.

The radius of curvature Rx of the concavely curved second portion 19 ofthe guide surface 16 of the crop-guiding element 15 is greater than theradius of curvature Ry of the concavely curved third portion 20 of theguide surface 16 of the crop-guiding element.

Furthermore, the wrap angle β of the concavely curved second portion 19is greater than the wrap angle γ of the concavely curved third portion20.

The concavely curved third portion 20 of the guide surface 16 of thecrop-guiding element 15 merges, according to the invention, into aconvexly curved fourth portion 21, said fourth portion 21 of thecrop-guiding element 15 preferably merging into a fifth portion 22 whichpreferably determines the maximum height c of the crop-guiding element15, as measured from the fastening portion 12 of the basic body 11.

Said maximum height c of the crop-guiding element 15 is, according tothe invention, between 24 mm and 30 mm, i.e. 27 mm±3 mm.

The above parameters of the chopping blade 10 permit an optimum guidanceof the harvested crop flow. The harvested crop is guided with littleacceleration work, thus making it possible to save on energy for theconveying process. The circulation of the harvested crop, i.e. the timeduring which the harvested crop is guided on the chopping blade 10 inthe region of the respective crop-guiding element 15 and thereforewithin the chopping drum, can be reduced. The guidance of the harvestedcrop can be undertaken in an ideal way for a wide variety of harvestedcrops, cut lengths and throughput rates by means of the abovegeometrical sizes.

The fourth portion 21 of the crop flow element 15 preferably has aradius of curvature Rz between 5 mm and 7 mm, i.e. 6 mm±1 mm. This alsoserves for the optimum guidance of the harvested crop.

The fifth portion 22 of the crop-guiding element 15 merges, preferablycontinuously or tangentially, into a rectilinearly running sixth portion23, said sixth portion 23 enclosing an angle δ between 23° and 27°, i.e.25°±2°, with the fastening portion 12 of the basic body 11. This is alsoof advantage in respect of optimum guidance of the harvested crop.

The crop-guiding element 15 is designed to be closed by means ofportions 24, 25 and 26 adjoining the sixth portion 23. The sixth portion23 of the crop-guiding element 15 thus merges into a convexly curvedseventh portion 24 and the seventh portion 24 into a rectilinearlyrunning eighth portion 25 which is adjacent to the fastening portion 12of the basic body 11 and via which the respective crop-guiding element15 is preferably connected to the fastening portion 12 of the basic body11.

Said eighth portion 25 merges into a ninth portion 26 which, at its endfacing away from the eighth portion 25, makes contact with the secondportion 19 of the guide surface 16 of the crop-guiding element 15.

The ninth portion 26 and the second portion 19 of the crop-guidingelement 15 are interconnected in an integrally bonded manner herepreferably by means of welding. Said welded connection is preferablyformed by laser welding.

FIG. 4 visualizes, with reference to the arrows 27, the advantageouseffect of the size of the distance a between the edge 17 of the guidesurface 16 of the crop-guiding element 15 and the transition edge 14 ofthe basic body 11 for guiding the harvested crop. The chopped harvestedcrop is first deflected in the transition region between the cuttingportion 13 and the fastening portion 12 of the basic body 11. This is ofadvantage both in respect of the guidance of the harvested crop and inrespect of a reduction in wear.

Even in the event of a worn cutting portion 13 and longer cut lengths,the chopped harvested crop does not strike against the crop flow element15. The distance a is selected here in such a manner that the choppedharvested crop is not conveyed too far into what is referred to as aturning circle of the chopping drum.

FIG. 5 visualizes, by way of an arrow 28, the guidance of the cutharvested crop at the transition into the first portion 18 of the guidesurface 16 of the crop-guiding element 15. The relatively shallow angleα causes a further deflection of the cut harvested crop onto the cropflow element 15, wherein, according to FIG. 6 , the harvested cropsubsequently passes in the direction of the arrow 29 into the secondportion 19 of the guide surface 16 of the crop-guiding element 15. Theconcavely curved portion 19 causes a further deflection of the choppedharvested crop in the direction of rotation DR of the chopping drum,with the chopped crop-guiding element 15 accelerating the harvested cropin the direction of rotation DR of the chopping drum.

Subsequently, according to FIG. 7 , the chopped harvested crop first ofall passes in the direction of the arrows 30 and 31 into the thirdportion 20 of the guide surface 16 of the crop-guiding element 15, withthe cut harvested crop being further deflected in the direction ofrotation DR by means of the reduced radius Ry of the third portion 20.In the direction of the arrow 31, the chopped harvested crop leaves thedrum turning circle owing to the rotational acceleration because of thecentrifugal force.

The radius Rz of the fourth portion 21 extends in the opposite directionand prevents residues of the chopped harvested crop from accumulating inthis region.

The crop-guiding element 15 prevents the chopped harvested crop frompenetrating on the inner side of the chopping blade 10 too great adistance into the drum turning circle. This would lead to a delayeddischarging of the harvested crop and thus to an extended circulation ofthe harvested crop. It is possible to prevent the harvested crop fromrotating within the drum housing. Finally, the transport of theharvested crop is configured such that it can be undertaken efficientlywith little requirement for energy.

The crop-guiding element 15 is preferably designed as a roll profilingelement.

During roll profiling, a blank sheet for the crop-guiding element 15 isdeformed and the surface thereof hardened. As a result, the crop-guidingelement 15 has increased hardness and a low susceptibility to wear.

According to an advantageous development, the crop-guiding element 15has a wear-protection coating at least on the first portion 18, secondportion 19 and third portion 20. Such a wear-protection coating ispreferably composed of a tungsten-carbide alloy which can be applied vialaser powder build-up welding. The susceptibility of the crop-guidingelement 15 to wear can thereby be further reduced.

The invention furthermore relates to a method for producing theabove-described chopping blade 10. During the production of the choppingblade 10, first of all the basic body 11 which has the fastening portion12 and the cutting portion 13, which is angled in relation to thefastening portion 12, is provided. This can be undertaken by the cuttingportion 13 being bent over in relation to the fastening portion 12.Furthermore, at least one crop-guiding element 15 which is connected tothe basic body 11 is provided. The crop-guiding element 15 is preferablydeformed by roll profiling of a sheet metal blank made of steel andbrought into the above-described contour consisting of the nine portions18 to 26. The first portion 18, the second portion 19 and the thirdportion 20 of the crop-guiding element 15 are preferably coated herewith a wear-protection coating, preferably with a tungsten-carbidealloy. The ninth portion 26 is preferably welded to the second portion19.

LIST OF REFERENCE SIGNS

-   10 Chopping blade-   11 Basic body-   12 Fastening portion-   13 Cutting portion-   14 Transition edge-   15 Crop-guiding element-   16 Guide surface-   17 Edge-   18 first portion-   19 second portion-   20 third portion-   21 fourth portion-   22 fifth portion-   23 sixth portion-   24 seventh portion-   25 eighth portion-   26 ninth portion-   27 Harvested crop guide-   28 Harvested crop guide-   29 Harvested crop guide-   30 Harvested crop guide-   31 Harvested crop guide

1. A chopping blade (10) of a forage harvester, having a basic body(11), which has a fastening portion (12) for fastening the choppingblade (10) to a chopping drum and a cutting portion (13) which is angledin relation to the fastening portion (12) and is intended for harvestedcrop to be chopped, having at least one crop-guiding element (15) whichis fastened to the fastening portion (12) and is intended for guidingchopped harvested crop, wherein a guide surface (16) of saidcrop-guiding element has a contour which is curved at least in sectionsand begins at a distance from the one transition edge (14) between thefastening portion (12) and the cutting portion (13), characterized inthat a distance (a) between the beginning of the guide surface (16) ofthe at least one crop-guiding element (15) and the transition edge (14)between the fastening portion (12) and the cutting portion (13) of thebasic body (11) is between 4 mm and 8 mm, the guide surface (16) of theat least one crop-guiding element (15) runs rectilinearly adjacent tothe beginning of said guide surface in a first portion (18) with alength (B) between 4 mm and 8 mm, wherein the first portion (18) of theat least one crop-guiding element (15) encloses an angle (α) between 18°and 22° with the fastening portion (12) of the basic body (11), thefirst portion (18) of the at least one crop-guiding element (15) mergesinto a concavely curved second portion (19), the radius of curvature(Rx) of which is between 21 mm and 25 mm and which has a wrap angle (β)between 29° and 33°, the second portion (19) of the at least onecrop-guiding element (15) merges into a concavely curved third portion(20), the radius of curvature (Ry) of which is between 18 mm and 22 mmand which has a wrap angle (γ) between 24° and 28°, the third portion(20) of the at least one crop-guiding element merges into a convexlycurved fourth portion (21), a maximum height (c) of the crop-guidingelement (15) is between 24 mm and 30 mm starting from the fasteningportion (12) of the basic body (11).
 2. The chopping blade according toclaim 1, characterized in that the fourth portion (21) of the at leastone crop-guiding element (15) has a radius of curvature (Rz) between 5mm and 7 mm, wherein the fourth portion (21) merges into a fifth portion(22) of the guide surface (16), which fifth portion runs parallel to thefastening portion (12) of the basic body (11) and defines the maximumheight (c) of the crop-guiding element (15).
 3. The chopping bladeaccording to claim 2, characterized in that the fifth portion (22) ofthe at least one crop-guiding element (15) merges into a rectilinearlyrunning sixth portion (23) which encloses an angle (δ) between 23° and27° with the fastening portion (12) of the basic body (11).
 4. Thechopping blade according to claim 3, characterized in that the at leastone crop-guiding element (15) is closed by portions (24, 25, 26)adjoining the sixth portion (23).
 5. The chopping blade according toclaim 3, characterized in that the sixth portion (23) of the at leastone crop-guiding element (15) merges into a convexly curved seventhportion (24) and the seventh portion (24) into a rectilinearly runningeighth portion (25) which is adjacent to the fastening portion (12) ofthe basic body (11).
 6. The chopping blade according to claim 5,characterized in that the eighth portion (25) of the at least onecrop-guiding element (15) merges into a ninth portion (26) which makescontact with the second portion (19) of the respective crop-guidingelement (15).
 7. The chopping blade according to claim 6, characterizedin that the eighth portion (28) is welded to the second portion (19). 8.The chopping blade according to claim 1, characterized in that the atleast one crop-guiding element (15) is a roll profiling element.
 9. Thechopping blade according to claim 1, characterized in that the firstportion (18), the second portion (19) and the third portion (20) of theat least one crop-guiding element (15) each bear a wear-protectioncoating.
 10. The chopping blade according to claim 9, characterized inthat the wear-protection coating is composed of a tungsten-carbidealloy.
 11. A method for producing a chopping blade according to claim 1,having the following steps: providing the basic body (11), which has thefastening portion (12) and the cutting portion (13) which is angled inrelation to the fastening portion (12), providing the at least onecrop-guiding element (15), fastening the at least one crop-guidingelement (15) to the basic body (11).
 12. The method according to claim11, characterized in that the at least one crop-guiding element (15) isprovided by roll profiling of a metal sheet.
 13. The method according toclaim 11, characterized in that the at least one crop-guiding element(15) is coated with a wear-protection coating at least on the firstportion (18), on the second portion (19) and on the third portion (20).